U.S. Pat. No. 4,307,143 to Meitner issued Dec. 22, 1981 describes meltblown microfiber wipers treated with a surfactant and embossed. Such wipers are demonstrated to have improved absorbency and wiping properties when compared with traditional wiper materials. U.S. Pat. No. 4,298,649 to Meitner dated Nov. 3, 1981 describes a multi-component nonwoven wiper having a layer of meltblown microfibers combined with a split film or fibrillated foam layer. This wiper exhibits low metal chip pick-up characteristics of particular interest in automotive finishing application.
This property is obtained without significant deterioration in wiping properties. U.S. Pat. No. 4,328,279 to Meitner and Englebert dated May 4, 1982 relates to a meltblown nonwoven wiper treated with certain surfactants to result in low sodium content of particular interest in electronics industry wiping applications. U.S. Pat. No. 4,041,203 to Brock and Meitner dated Aug. 9, 1977 relates to nonwoven fabrics and sterile wrapper materials made by combining layers of meltblown thermoplastic fibers with one or more continuous thermoplastic filament layers. The disclosure recognizes that such materials can be treated for absorbency and used in wiper applications. U.S. Pat. No. 4,196,245 to Kitson, Gilbert, Jr., and Israel dated Apr. 1, 1980 relates to a composite nonwoven fabric useful in disposable surgical items and which can comprise one or more meltblown layers loosely bonded to one or more spunbonded layers.
The preparation of polyolefin microfiber webs is known and described, for example, in Wendt, Industrial and Engineering Chemistry, Vol. 48, No. 8 (1956), pp. 1342 through 1346, as well as in U.S. Pat. Nos. 3,978,185 to Buntin, et al., issued Aug. 31, 1976; 3,795,571 to Prentice, issued Mar. 5, 1974, and 3,811,957 to Buntin issued May 21, 1974. The Buntin, et al. patent further discloses that mats of meltblown polyolefins are useful in wiping cloths and hydrocarbon absorption materials. Composite materials including fibers and/or particulates incorporated in a meltblown fiber matrix are described in U.S. Pat. No. 4,100,324 to Anderson, Sokolowski, and Ostermeier issued July 11, 1978.
Production of substantially continuous filaments is also known, and illustrative techniques are set forth in U.S. Pat. Nos. Kinney 3,338,992 and 3,341,394, Levy 3,276,944, Peterson 3,502,538, Hartmann 3,502,763 and 3,509,009, Dobo 3,542,615 and Harmon Canadian Pat. No. 803,714. Reference may also be had to the above-identified Brock and Meitner U.S. Pat. No. 4,041,203 for methods of producing combinations of meltblown thermoplastic fibers and continuous filament thermoplastic fibers. Commonly assigned U.S. Pat. No. 4,340,563 to Appel and Morman dated July 20, 1982, describes an alternative method for producing continuous filament thermoplastic webs.
Wipers made from a matrix of meltblown fibers having incorporated therein a mixture of staple fibers including synthetic and cotton fibers are described in U.S. Pat. No. 4,426,417 to Meitner and Hotchkiss dated Jan. 17, 1984. Laminate wiper materials including a meltblown middle layer with or without other fibers mixed therein between spunbonded outer layers are described in U.S. Pat. No. 4,436,780 to Hotchkiss, Notheis, and Englebert dated Mar. 13, 1984. A laminate material useful for wiping applications and including a layer of meltblown fibers having other fibers or particles mixed therein combined with at least one meltblown layer is described in published European Application No. 0205242 dated to Storey and Maddern published Dec. 17, 1986.